fs/quota: remove unused macro

__QUOTA_V2_PARANOIA  macro is never used. better to remove it.

Link: https://lore.kernel.org/r/1579602334-57039-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Jan Kara <jack@suse.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

fs/quota/quota_v2.c

@@ -22,8 +22,6 @@ MODULE_AUTHOR("Jan Kara");
 MODULE_DESCRIPTION("Quota format v2 support");
 MODULE_LICENSE("GPL");
 
-#define __QUOTA_V2_PARANOIA
-
 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
 static int v2r0_is_id(void *dp, struct dquot *dquot);